Self-healing Behavior of 2D C/SiC Modified by Partial Boron Carbide Matrix after Annealing at Low Temperature in Wet Oxygen

Oxidation behavior of 2D C/SiC composites modified by boron carbide self-sealing matrix was investigated at low temperature of 700°C in wet oxygen. Oxidation tests were conducted under a creep stress of 100MPa up to 60h. Microstructural evolution of the modified composites was explored by SEM and TEM. Results show that the modified composites hold better inoxidizability than the conventional C/SiC composites, which is caused by the self-heal of matrix cracks (and the stress enlarged ones) with oxidation induced B2O3 and the inhibition of C oxidation. The unoxidized B-C is identified as a coagent of B2O3 to fulfill the healing. Healing ability of the modified matrix is preserved in 60h and is valid for longer periods of time.